The switch and execution to looter shooter didn't feel right. It took a while to get used to it from the first game (2013).
Enemies drop so many possible upgrades for your weapons that you feel overwhelmed and it makes the game more complicated than it should be. You literally will acquire over hundreds of upgrades if you collect them all from fallen enemies. The game doesn't make it that easy to quickly compare upgrades and it didn't seem like you could view already used upgrades vs unused. Therefore it takes too much time to go through them all. The "base" where you can craft, buy and sell your upgrades or weapons also felt dull and without character. All the maps have loads of scattered chests at every third or fourth corner which didn't make it feel satisfying to get ammo or cash from them at all. Cash is also scattered around the map a lot. It felt pretty pointless to pick any of it up since enemies dropped both cash and ammo.
The gory action is fun though and so are the different weapons you can choose from. The special sword attacks are still there from the first game and it was cool to see more variability in melee weapons and other weapons too. All the different enemies were nice but the boss fights felt average.
The game uses the same maps for different missions often. After playing through half the game you realize this and just try to avoid the enemies to get to your goal, either by Vanishing (invisible) through everyone or simply going around the enemies which you could do more than half the time. It made the enemies pointless after you had leveled up enough unless the mission made it necessary to kill the enemies to advance.
The story was a mess. When you create a sequel only because of the success of the first game with little vision to continuity you just get sloppy writing and a story with holes, cliches and forgettable characters, including Lo Wang and other characters from the first game. Most of the dialogue felt out of place with forced comedy which wasn't funny like in the first game. The ending was pretty bad and leaves you with no answers about what the hell happened. The story being the way it was was my biggest disappointment.
I haven't tried co-op. Joined the only guy that was hosting a game where I had higher ping but multiplayer felt okay for the few minutes I played I guess.
I bought this game at the time out of sheer excitement because of how much I loved the first game. SW2 may have upheld the quality of gameplay, and even improved it, from the first game. Everything else was lackluster.
Only buy this game on a very good discount if you're a fan of the first one.